The Flaw of Averages (2020)

The mean of a set of measures is only characteristic of those measures if the error in each is random, ie., if there&#x27;s equally probably positive errors, vs. negative.<p>We teach means as something somehow fundamental and commonly useful; but they&#x27;re rarely useful and highly derivative.

Discussed at the time:<p><i>Forecasting with uncertainty</i> - <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22842847">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=22842847</a> - April 2020 (20 comments)

&gt; but it&#x27;s very rare for everything to go wrong all of the time.<p>I think in reality the inputs to these models are a lot less independent than they would like. Even in the example at the start of the article, I suspect that for most folks income from a side hustle and investment rate of return are both highly correlated to the overall economic conditions. Attempting to add statistical rigor to something as open ended as predicting the future feels quixotic.

This is kind of rude in that it uses the term &quot;The Flaw of Averages&quot; as well as some ideas and even an image from the book by the same name by Sam Savage and Jeff Danziger but gives them no credit. If you can&#x27;t come up with your own expressions and drawings then you should credit the source that you end up using.

At the end he gives two ways running Monte Carlo simulations, spreadsheet plugins, and his own app Casual. Surely there are more. Are there other tools for Monte Carlo sims that HN&#x27;ers use and like? Preferably local FOSS apps?